The first problem with ley lines is defining what points shall be considered
significant on a ley. Alfred Watkins had a points system which
graded the markers. Paul Screeton's Ley Hunter definition
is probably as good as any here.. This is always going to be subjective, but they fall into
two classes - direct markers and indirect markers.

Direct markers are therefore sites of obvious prehistoric provenance. Indeed,
one variant of the ley theory, John G Williams' SCEMB
lines, limits itself to
just those elements. Ley researchers also accepted indirect markers, such as
some churches and crossroads, on the ground that these were often sited on
previous prehistoric sites.

The essential thesis of
leys is that prehistoric man sited many of his markers along
straight lines on the ground.

Straight lines would
ideally imply a great-circle route, though over the 10-mile stretch of
significance for leys a straight line on the OS map projection would be
acceptable.

Accepting these, the factual questions boil down to

Are the described sites on a straight line as stated, within an acceptable
accuracy?

Is a straight line in the field the same as a straight line on the map?

How does the number of ley lines in an area compare to the number of
alignments you would get from the same number of significant points as the original
map had, but scattered at random.

Softer questions are

Would Neolithic Man be able to align his monuments with such accuracy?

and perhaps the killer question - why go to all this trouble?

Most of these are contentious, though it was the first and last factual points that
Williamson & Bellamy showed devastatingly to be the key weakness of the ley
theory.

The "acceptable accuracy" of point 1 is a practical issue, since
the symbol for many types of site varies. A church symbol occupies 50 yards by 45 yards
on the ground on a 1:50,000 scale map, and even the finest pencil dot is
17.6 yards in diameter on that scale The only sites that
approximate a dot are standing stones, wells and churches without towers.
Obviously a real church is often even larger than the symbol, but it's extent
means that there is more chance of such an object intersecting a ley than
the width of the pencil line would seem to indicate.

This looks trivial, but shows how one's intuitive grasp of the uniqueness of
a ley is at fault. Williamson & Bellamy showed how for example
increasing the size of two out of 11 point elements changed the number of leys
in their example from four to nine.

The coup the grace came when Williamson & Bellamy took OS sheet 173 (Swindon,
Devizes in Wiltshire) which includes Avebury.
They looked for leys, coming up with the following.

points

# of leys

6

130

7

44

8

14

9

5

which is a pretty convincing confirmation of the ley system. Until you take
into account the number of leys they discovered when they randomised the
positions of these points within their grid squares (or four squares in the case
of larger area sites)

Real map

Randomised

points

# of leys

# of leys

6

130

127

7

44

48

8

14

12

9

5

6

That's it. 'nuff said. End of story. Leys are toast - at least as far as
searching for them as straight line alignments using maps! Of course, I would have liked to have seen the
exact leys Williamson & Bellamy found, the positions of their mark points in
Grid refs and the positions of their randomised mark points to reproduce their
results and confirm no undue fiddling went on. Yet is is the problem of the
area points, and the subtle and counterintuitive way they make leys so much more
common than one would expect, which is where I found their case strongest. I have not heard of a ley comprising more than
five megalithic point marks.

Their work doesn't fundamentally disprove that some prehistoric stones were aligned intentionally, but what it does do is
state you simply can't tell if they were from the fact that alignments do exist. You can't eliminate Type 1 errors, so you can't tell intention from finding straight
line alignments, because straight line alignments can be found in a randomised plot which has no intentional alignments by definition. It wouldn't be so bad
if the alignments tended towards one direction, like recumbent stone circles tend to have the recumbent stone aligned to the south-west, so the arc of the southernmost moon grazes the recumbent stone. But no such anisotropy is found with leys.

The end of the dream

Leys didn't die - they faded away and became distorted into nothingness. The conversion from Watkins' impossibly
straight pathways through forests, across hills and rivers and through bogs to
the energy lines of the 1970s coincided with a change in editorship of "The
Ley Hunter" to Paul Devereux. Disturbed by the subjectivity of the dowsing
approach, and yearning for academic recognition, Devereux launched the
"Dragon Project" which was an attempt to measure these subtle forces via a
range of effects - magnetic fields, electric fields, nuclear radiation
detectors, ultrasound and others physical means.

The results of the physical monitoring part of the Dragon project were inconclusive, though
once again the difference between amateur research and professional research
shows in the total absence of published documentation, other than Paul Devereux's book
Places of Power which is a summary of the
work aimed at non-technical readers.

Don Robins, one of the initial researchers, also
wrote an earlier book before the project was finished titled Circles of Silence
which indicated a more positive result. Nowhere are details of the equipment used,
the methodology detailed or field notes described in sufficient detail to
attempt to replicate any of the work. This is a shame, particularly as the book
gives the impression that there were observations worth following up. Danny Sullivan
summed it up that "The conclusion was that apart from variable
and rare anomalous features in the earth's geomagnetic field, natural
background radioactivity and ultrasound there was no evidence at all for an
unknown 'earth force'".

The 1983
Williamson & Bellamy book seems to have finished off the subject in terms of
ancient energy networks, though you
still read widely on the web and in books words to the effect of "Leys are lines of
mysterious ancient power, along which prehistoric man aligned his
monuments". The ley hunters up to mid-1980s went on an intuitively very
reasonable premise - that the alignments were significant and unlikely to occur
by chance. A premise which turned out to be incorrect. After this, evidence was
mustered from disparate and unconnected ancient societies across the whole
world, to draw a tenuous conclusion.